This invention relates to rinse-off hair treatment compositions and to their use in the treatment of hair.
Shampoo compositions are generally formulated with highly effective cleansing surfactants, typically anionic surfactants, and do not in themselves provide much conditioning or styling benefit to the hair. In fact, basic shampoo formulations which have not been supplemented with specific conditioning or styling agents have a tendency to leave the hair in a cosmetically-unsatisfactory condition with regards to manageability and stylability. The hair tends to have a harsh, dull and dry feel, often referred to as xe2x80x9ccreakxe2x80x9d, is often difficult to comb, in either the wet or the dry state, typically has poor brushing properties, and tends to have poor set-retaining abilities.
This has resulted in the use of products containing specific conditioning and/or styling agents. Such agents are generally applied separately after shampooing and rinsing the hair, for example, in the form of conditioner formulations or styling mousses etc. Alternatively, conditioning and/or styling agents have been incorporated into the shampoo formulations. Although the latter approach provides the advantage of removing the need for a separate conditioner or styling treatment, the conditioning and/or styling agents are not always compatible with the shampoo ingredients, especially the anionic surfactant. This can result in the cleansing action and/or cosmetic benefit being compromised.
One of the most common methods for imparting styling benefits to the hair has been the use of hair fixative agents, such as high molecular weight polymers. The problem with using such agents is that they have a tendency to negatively impact on conditioning attributes such as wet and dry stage clean feel and smoothness. In fact, they can result in a sticky feel to the hair.
Conventional styling polymers are typically water soluble. This means that when incorporated into a shampoo or conditioner which is rinsed off the hair, there is a tendency for the styling polymer to be washed away to a greater or lesser degree with the shampoo/conditioner. Hence, most styling products are leave-in products which are applied to the hair as post-shampoo/conditioner treatments.
The problem being addressed by the present invention is the provision of rinse-off hair treatment compositions which impart styling benefits, and in particular body benefits on the hair, but which do not compromise the cleansing action of the shampoo and which do not negatively impact on the conditioning attributes of the hair. The body benefits or attributes the present invention is looking particularly to provide include root lift, increased hair volume, bounce, control (i.e. ease of styling) and manageability, i.e. maintenance of style without undue stiffness and negative sensory feel. Such body attributes are particularly attractive to people with fine or long, weighty hair.
One way in which this problem has been addressed in the past has been to include conditioning agents, for example silicones and cationic surfactants, in the compositions, to counter the negative effects of the styling agents. Although such conditioning agents do provide substantial improvements in for example the wet and dry combing properties of the hair and in the smoothness of the hair, they tend to have a negative effect on many of the attributes associated with hair body.
An alternative approach has been the use different forms of styling agents such as small particulate materials. Such an approach is described, for example, in our unpublished PCT International Patent Application No. PCT/GB00/04020. This document describes the use of small hard particles, and in particular colloidal silica, in hair treatment compositions to impart body and volume to the hair. Although providing significant styling benefits, the use of these materials can still lead to small levels of sensory negatives, such as for example a dry feel to the hair.
JP 10144622 (Toshiba Silicone) discloses cosmetic compositions containing particles consisting of colloidal silica cores surrounded by silicone shells which may be used on the skin or hair. Hairdressing lotions, hair creams and cleansing compositions such as a shampoo, rinse and conditioner are disclosed as suitable cosmetic compositions in which the particles can be utilized.
We have now found that the inclusion of a certain level of silicone pressure sensitive adhesives (silicone PSA) in the hair treatment formulations provides substantial styling go benefits, in particular with regards to imparting body attributes to the hair. Furthermore, the conditioning attributes of the hair are not adversely affected by the use of hair compositions containing these silicone PSA""s and there is no necessity to incorporate additional conditioning agents or specialized surfactant systems. The compositions of the present invention are also stable.
The incorporation of silicone PSA""s into the hair treatment compositions of this invention leads to substantive improvements in the body of the washed and optionally conditioned hair, especially if a subsequent styling regime is followed. The compositions impart body attributes, such as root lift, volume, bounce and manageability, in the absence (or substantial absence) of a styling polymer, which leads to compositions which have a styling benefit, but nevertheless do not suffer from the sensory negatives (e.g. stickiness and/or dry feel) which are associated with prior styling compositions which are based on, for example, a styling polymer.
Accordingly, this invention provides an aqueous hair treatment composition comprising:
a) at least one silicone pressure sensitive adhesive
b) a material selected from the group consisting of a suspending agent, a hair conditioning agent and a hair cleansing agent.
Preferably, the resulting hair care composition will increase static friction of dry hair by at least about 10%, and will increase in the dynamic friction of dry hair by no more than 100% or leave said dynamic friction unchanged or decrease said dynamic friction. This invention provides for the use of silicone PSA""s as defined herein in a hair treatment composition to impart body without compromising conditioning.